This proposal discusses the evaluation and development Real time PCR assays using novel breast cancer markers for the diagnosis and prognosis of human breast cancer. Breast cancer is second only to lung cancer in deaths among women in the U.S. Good prognosis depends on the early detection of the disease. However, the sensitivity and the specificity of the current available diagnostic markers is not sufficient. Using improved state of the art technology, differential display PCR and cDNA library and PCR subtraction methods, we have identified 5 novel breast cancer markers and established their tissue specificity and potential presence in micrometastases using Real time PCR. These novel genes will be further evaluated alone and/or in combination to determine the optimal combination of genes for use in Real time PCR assays to detect micrometastases and provide improved diagnosis/prognosis of breast cancer. Real time PCR with these genes on different stage tumors and micrometastases has already been achieved at Corixa and will be expanded and standardized assays developed. This in combination with collaborations with key investigators in the area of breast cancer and access to an extensive blood and tissue bank should enable the goals and objectives of this proposal to be achieved. PROPOSED COMMERCIAL APPLICATION: The proposed studies will lead to commercialization of a high throughput RT-PCR assay for diagnosis and /or prognosis of breast cancer. Such tests would be marketed both in the U.S. and worldwide. The estimated world wide market for such a tests is $200-300 million/year.